Snow vehicle

ABSTRACT

A snow vehicle is disclosed comprising a vehicle frame, a propulsion unit coupled to the frame, and at least one front ski steered by a steering mechanism. The front of the vehicle includes a first front suspension and a second front suspension coupled to the ski. The rear suspension includes a bumper assembly preventing bottoming out of the rear suspension. The rear suspension is coupled to the vehicle frame such that the longitudinal spacing between the vehicle frame and rear suspension is adjustably controllable.

The present application is a continuation of patent application Ser. No. 15/165,862 which is a continuation-in-Part of patent application Ser. Nos. 14/935,224 and 14/935,265, the subject matter of which are disclosed herein by reference.

BACKGROUND

The present disclosure relates to snow vehicles including snowmobiles and or snow bikes.

Many types of vehicles are configured with tracks to drive in the snow. Regardless of whether the vehicle is a snowmobile or a wheeled vehicle converted to a tracked vehicle, tracked vehicles typically include a drive shaft mounted to a suspension system that supports the endless track. The drive shaft typically includes drive sprockets that engage the endless track. Irregularities in the snow and ice covered terrain cause the suspension system to move. Shock absorbers are typically used to absorb the movement of the suspension system. Common suspension systems are configured to collapse towards the tracked vehicle when absorbing the movement. However, in some situations, the irregularities in the terrain cause movement in the suspension away from the tracked vehicle that is not accommodated by the suspension system.

In the case of snow bikes, the front suspension comprises the suspension of the motorbike or dirt bike, that is, a front shock absorber. In the case of snowmobiles, the front suspension is typically includes two control arms, also known as double A-arms. However the front snowmobile suspension can also be a trailing arm suspension. The suspension described herein would typically supplement any of the front suspensions discussed above, although it could also be the primary suspension.

One such snow vehicle is shown in our U.S. Pat. No. 8,910,738, the subject matter of which is incorporated herein by reference. This patent discloses a conversion of a motorbike into a snow vehicle where the motorbike powertrain is utilized to power the track of the converted snow vehicle.

SUMMARY

In a first embodiment, a snow vehicle comprises a vehicle frame; a propulsion unit coupled to the frame; at least one front ski; a steering mechanism coupled to the frame; a first front suspension coupled to the frame; a second front suspension coupled to the at least one ski; a rear suspension coupled to the frame, the rear suspension comprising: at least one slide rail; at least one control arm coupled between the slide rail and the frame; at least linear force element coupled between the slide rail and the frame; and at least one carrier roller coupled to the at least one slide rail and the frame; a bumper assembly preventing bottoming out of the rear suspension; and a drive system comprising a drive track slidably guided by the at least one slide rail and drivably coupled to the propulsion unit.

In another embodiment, a rear suspension for a snow vehicle, comprises at least one slide rail; a frame; at least one control arm coupled between the slide rail and the frame; at least linear force element coupled between the slide rail and the frame; at least one carrier roller coupled to one of the slide rail and the frame; a drive system comprising a drive track slidably guided by the at least one slide rail and drivably coupled to the propulsion unit; and a bumper assembly coupled to the rear suspension and positioned to prevent contact of the at least control arm and a remaining portion of the rear suspension.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in relation to the drawing figures where:

FIG. 1 is a side view of one of the embodiments of snow vehicle as disclosed in the present disclosure;

FIG. 2A shows a left front perspective view of the front suspension coupled to the snow vehicle;

FIG. 2B is a front suspension similar to that of FIG. 2A showing the front suspension coupled to a conventional snowmobile;

FIG. 3 is a front left perspective view of the suspension assembly;

FIG. 4 is a rear right perspective view of the suspension assembly of FIG. 3;

FIG. 5 is a view similar to that of FIG. 3 showing the suspension in an exploded manner;

FIG. 5A is an enlarged portion of the linkage assembly shown in FIG. 5;

FIG. 5B is an enlarged portion of the shock absorber mounting as shown in FIG. 5;

FIG. 6A shows a side view of the front suspension coupled to a ski in the fully extended position;

FIG. 6B shows the front suspension of FIG. 6a in a full trounce position;

FIG. 7 shows a front left perspective view of the rear suspension shown in FIG. 1;

FIG. 8 shows a rear right perspective view of the rear suspension shown in FIG. 7;

FIG. 9 shows a left side plan view of the suspension shown in FIG. 7; respectively;

FIG. 10 shows a left side plan view of the suspension shown in FIG. 7;

FIG. 11 shows a front left perspective view of the rear suspension of FIG. 7 in an exploded manner;

FIG. 12 shows a front left perspective view of an upper frame portion of the rear suspension assembly;

FIG. 13 shows a rear right perspective view of the upper frame portion shown in FIG. 12;

FIG. 14 shows a rear suspension coupler coupled to the slide rails;

FIG. 15 shows an enlarged perspective view of the bumper assembly;

FIG. 16 is an exploded view of the bumper assembly of FIG. 15;

FIG. 17 is a cross-sectional view of the bumper assembly shown through lines 17-17 of FIG. 15;

FIG. 18 shows a side view of the bumper assembly in full extension (dotted lines) and in full trounce (solid lines);

FIG. 19 shows a front left perspective view of a second embodiment of the rear suspension;

FIG. 20 shows an enlarged portion of the front of the suspension shown in FIG. 19;

FIG. 21 shows an enlarged view of the chain tensioner located at the front of the rear suspension assembly of FIG. 19;

FIG. 22 shows an exploded view of the chain tensioner shown in FIG. 21;

FIGS. 23 and 24 show opposite views of the chain tensioner bar;

FIGS. 25A and 25B show extreme positions of the chain tensioner in use;

FIG. 26 shows a front perspective view of the bumper assembly of the rear suspension of FIG. 19;

FIG. 27 shows an enlarged view of the mounting of the bumper assembly to the rear control arm;

FIG. 28 shows an exploded view of the bumper assembly of FIG. 27;

FIG. 29 shows an underside perspective view of the rear control arm;

FIG. 30 shows a side view of the bumper assembly in contact with the slide rail in a trounce position (solid lines) and prior to contact (dotted lines);

FIG. 31 shows a front perspective view of a third embodiment of rear suspension;

FIG. 32 is an exploded view of the rear suspension of FIG. 31;

FIG. 33 shows an enlarged view of main frame portion of the third rear suspension;

FIG. 34 shows a rear perspective view of the main frame portion of FIG. 33;

FIG. 35 shows a rear perspective view of the suspension assembly coupled to the rear control arm;

FIG. 36 shows a front perspective view of the suspension assembly shown in FIG. 35;

FIG. 36A shows an alternate embodiment of the rear suspension assembly of FIG. 36;

FIG. 37 shows a rear perspective view of the suspension assembly shown in FIG. 36;

FIG. 38 shows an exploded view of the suspension assembly shown in FIGS. 36 and 37;

FIG. 39 shows the suspension assembly of FIGS. 37 and 38 when in an extended position;

FIG. 40 shows the suspension assembly of FIG. 39 when in the trounce position;

FIG. 41 shows an enlarged front left perspective view of a front end of FIG. 31;

FIG. 42 shows a partially exploded view of FIG. 41; and

FIG. 43 shows an enlarged front right perspective view of a front end of FIG. 31.

FIG. 44 shows a right front perspective view of an alternate front suspension with two skis and an independent suspension for each ski;

FIG. 45 shows a right rear perspective view of the front suspension of FIG. 44;

FIG. 46 shows a side perspective view of the front suspension of FIG. 44;

FIG. 47 shows an exploded view of the front suspension of FIG. 44;

FIG. 48A is an enlarged portion of the spindle assembly shown in FIG. 47;

FIG. 48B is an enlarged portion of the linkage assembly shown in FIG. 47;

FIG. 48C is an enlarged portion of the shock absorber mounting as shown in FIG. 47;

FIG. 49 shows a right front perspective view similar to that of FIG. 44 with the left ski lifted relative to the right ski;

FIG. 50 shows a right rear perspective view with the left ski lifted relative to the right ski;

FIG. 51 shows a right side perspective view with the left ski lifted relative to the right ski;

FIG. 52 shows a left side view with the left ski lifted relative to the right ski;

FIG. 53 shows a right side view with the left ski lifted relative to the right ski;

FIG. 54 shows a rear view with the left ski lifted relative to the right ski to clear an obstacle;

FIG. 55 shows a front view with the left ski lifted relative to the right ski to clear an obstacle; and

FIG. 56 shows a front view with the left ski lifted relative to the right ski to ride on a slope.

DETAILED DESCRIPTION OF THE EMBODIMENTS

With reference first to FIG. 1, a snow vehicle is shown generally at 2 as comprised of a motorcycle portion 4 having a propulsion unit 5, which is shown as a two-cylinder motorcycle engine, a frame 6, an operators seat 8, and a steering assembly 10 which includes a front fork 12. A first suspension member is shown at 14 as a shock absorber assembly axially coupled with the forks 12. A second front suspension assembly is shown at 16 which couples the steering assembly 10 directly to a ski 18. A rear suspension assembly 20 is shown having an upper frame portion 22, slide rails 24, side panels 26, control arms 28, 30, linear force elements 32 and 34 (shown as shock absorbers) and an endless belt or drive track 36. With reference still to FIG. 1, the snow vehicle 2 includes a foot peg 38 for the rider to position their foot thereon during a ride.

With reference now to FIGS. 2A and 3-5, the front suspension assembly 16 will be described in greater detail. As shown best in FIGS. 3 and 4, front suspension assembly 16 generally includes a spindle body 40, a lower linkage portion 42, and a mounting portion 44. As shown best in FIG. 5, spindle portion 40 is generally comprised of two plates 50 and 52 where each plate includes a plurality of apertures. Namely, plate 50 includes apertures 50 a-50 g together with an enlarged aperture at 50 h. Likewise, plate 52 includes apertures 52 a-52 g and an enlarged aperture at 52 h. Spindle portion 40 also includes a plurality of spacers to space the plates 50 and 52 apart, namely spacers 54 a, 54 b, 54 c, and 54 g. An enlarged spacer is provided at 54 h. It should be noted each of the spacers 54 a, 54 b, 54 c, and 54 g are somewhat spool-shaped having an enlarged head portion 56 at each end as well as threaded openings 58 at each end. Enlarged spacer 54 h is embossed at each end to define a reduced diameter section 60 defining shoulders 62.

Thus, the spindle portion may be preassembled by placing the reduced diameter portion 60 of spacer 54 h into respective apertures 50 h and 52 h. This positions the reduced diameter portion 60 through the corresponding apertures 50 h and 52 h as shown in FIGS. 3 and 4. Spacers 54 c and 54 g may then be aligned with corresponding apertures 50 c, 52 c; and 50 g, 52 g. Fasteners and washers may then be positioned against plates 50 and 52 to retain the two plates together and coupled to the spacers. Namely, fastener 70 c and washer 72 c may be aligned with aperture 52 c and brought into threaded engagement with threaded aperture 58 of spacer 54 c. Likewise, fasteners 70 g and washers 72 g may be received through apertures 50 g and 52 g to be received into the threaded ends 58 of spacer 54 g. The fasteners should be brought into engagement with the threaded apertures of their corresponding spacers but not fully torqued down at this position as other spacers and assembly is required within the spindle assembly.

With reference still to FIG. 5, mounting portion 44 is shown including clamp halves 80, 82; 84, 86. Each of the pairs of clamp halves includes semi-cylindrical openings which may encompass the front forks of the motorcycle frame as described above with reference to FIG. 1. Thus, spacers 54 a and 54 b are now aligned with respective pairs of apertures 50 a, 50 b; 52 a and 52 b; and fasteners 70 a and 70 b are received through their respective apertures as shown in FIG. 5. This brings fasteners into engagement with the threaded ends 58 of the corresponding spacers 54 a and 54 b to a position where the clamp may be closed.

With reference now to FIG. 5A, the link assembly 42 is shown and will be described in greater detail. As shown best in FIG. 5A, link assembly 42 includes front links or control arms 100 and rear links or control arms 102. Each control arm 100 includes an upper coupling 100 a and a lower coupling at 100 b. Likewise, control arms 102 include upper couplings at 102 a and lower couplings at 102 b. Each of the upper couplings 100 a and 102 a receive sleeves 104 which are profiled to be received in the couplings 100 a, 102 a. Spacers 106 and 108 respectively, are then inserted through corresponding couplings 100 a, 102 a and into sleeves 104. Likewise, spacer 108 is received into couplings 102 a, and into sleeves 104. Thus, control arms 100 and 102 may be aligned with respective apertures 50 e, 52 e, and 50 f, 52 f (FIG. 5) and fastened to the spindle assembly by way of fasteners and washers 70 e, 72 e and 70 f, 72 f.

With reference again to FIG. 5A, linkage assembly 42 further includes a knuckle 110 having a front pivot coupling 110 a having an aperture at 110 b and a rear pivot coupling 110 c having an aperture 110 d. Sleeves 112 may be received in lower couplings 100 b of control arms 100 (in the orientation shown in FIG. 5A) and then couplings 100 b may be received in alignment with apertures 110 b whereupon fasteners 114 a and washers 114 b may be aligned with threaded apertures 110 b to couple control arms 100 with the knuckle 110. In a like manner, sleeves 116 may be received in lower couplings 102 b (in the orientation shown in FIG. 5A) whereby couplings 102 b and sleeves 116 are received over rear pivot coupling 110 c and in alignment with threaded apertures 110 d. Thereafter, fasteners 120 a and washers 120 b may be aligned with sleeves 116 to couple alignment arms 102 with knuckle 110.

Finally, with reference to FIG. 5B, linkage 42 further includes a shock absorber 124 having a lower coupling at aperture 124 a and an upper coupling at aperture 124 b. Split sleeves 126 include reduced diameter portions 126 a and threaded apertures at 126 b. Split sleeves 126 may be positioned with reduced diameter portions 126 a in apertures 124 b and the shock may be coupled to the spindle assembly by way of fasteners 70 d and washers 70 e positioned through apertures 50 d (FIG. 5) and into threaded engagement with threaded apertures 126 b. The lower aperture 124 a of shock 124 may then be coupled to bracket arms 102 c as shown in FIG. 5B. Sleeves 130 are positioned with reduced diameter portions 130 a within the shock aperture 124 a. The sleeves 130 and the shock aperture 124 a are then aligned with apertures 102 d whereupon fastener 140 may be received through sleeves 130, apertures 102 d and receive a fastener 142 and lock washer 144. Thus, the entire assembled second suspension system 16 is shown in FIGS. 3 and 4 where knuckle 110 is shown as providing an aperture 110 e for coupling to ski 18 as shown above in FIG. 2A. That is, ski 18 includes ski rails 18 a whereby a pin 18 b may be received through the rails and into aperture 110 e for retaining ski 18 to the second suspension system 16. Ski 18 could be similar to that shown in U.S. Pat. No. 8,381,857, the subject matter of which is incorporated herein by reference.

Thus, in operation and with reference to FIGS. 6A and 6B, ski 18 is shown in a fully extended position in FIG. 6A and in a full trounce position in FIG. 6B. As shown in FIG. 6B, control arms 100 and 102 are shown collapsed with the shock absorber 124 in a stroked position. Advantageously, the ski is lifted up and rearwardly relative to spindle assembly 40. It is lifted upwardly in the sense that it rotated (in the clockwise sense as viewed in FIG. 6B). It is rotated in the range of 1-5°. It also moves rearwardly, for example, the position of the pin 18 b which couples the ski to knuckle 110 moves rearwardly from the positions shown in FIG. 6A to the position shown in FIG. 6B. That is, the distance in FIG. 6A between the upper pivot point of front control arm 100 (about fastener 70 e) is shown as X₁, whereas in FIG. 6b the distance is shown as X₂, where X₂ is greater than X₁. This provides an enhanced suspension system in that the ski is lifted up and rearward; for example, if the snow bike is going over a rock or log, the ski is lifted up and over the log rather than pushing the ski into the log. This movement also reduces the friction between the ski and the snow due to the lifting of the ski.

It should be understood that the spindle assembly may also be usable on a conventional snow mobile, and as shown in FIG. 2B, spindle 16′ is shown coupled to upper and lower alignment arms or control arms 150, 152, where upper control arm 150 is coupled to spindle assembly 16′ by way of a ball joint at 154. Although not shown in FIG. 2B, lower control arm 152 would also be coupled by way of a ball joint to spindle assembly 16′. It should be further understood that spindle assembly 16 or 16′ could be adapted for use with a trailing arm type snowmobile suspension of the type shown in U.S. Pat. No. 6,328,124, the subject matter of which is incorporated herein by reference. A full description of the front suspension is described in our co-pending patent application Ser. No. 14/935,265, filed Nov. 6, 2015, incorporated herein by reference.

With reference now to FIGS. 7-19, rear suspension 20 will be described in greater detail. As shown, and in particular with reference to FIGS. 9-11, rear suspension 20 includes an upper portion 154, an intermediate suspension portion 156 and a lower portion 158. As shown, intermediate suspension portion 156 is coupled to the upper and lower portions 154, 158 in a four bar linkage fashion allowing the upper and lower portions 154, 158 to move relative to each other in dampened fashion. In addition to the items already described on rear suspension 20, rear suspension 20 includes a drive system 160 which is input from the propulsion unit 6 by way of a chain; a belt drive system 162 driven by drive system 160 through gear casing or chain case 164 and a chain tensioner 166 (FIG. 7) which is moveable into the drive chain for taking up slack. As shown best in FIG. 8, a disc brake 168 is shown on the backside of drive system 160 for braking the snow bike. Furthermore, a bumper system 170 is shown which as described herein, prevents a crash between upper and lower portions 154, 158 of the rear suspension 20.

With reference now to FIGS. 12 and 13, upper frame member 22 will be described in greater detail. As shown, upper frame 22 includes two longitudinal frame members 180 extending lengthwise the entire length of the frame member 22. Frame member 180 is interrupted at a front end thereof by way of front cross bar 182 which couples to a front end portion 180 a of frame member 180. Frame portions 180 b extend forwardly from cross-bar 182 and include front coupling members 184 which couple to a rear section of motorcycle portion 4 (FIG. 1). Frame members 186 reinforce frame members 180 b and cross tube 182 in a triangular manner, and while shown as frame tubes, gussets could also be used such as a triangular plate portion welded in place between frame members 180 b and cross tube 182. As shown best in FIG. 13, cross tube 190 couples together frame members 180, where an end of cross tube 190 includes a threaded aperture at 190 a. As shown best in FIG. 12 a cross tube portion 192 is positioned above frame member 180 and includes a threaded aperture at 192 a. As shown in both FIGS. 12 and 13 a cross tube 196 is positioned rearwardly of cross tube 190 and also couples together frame members 180. Cross tube 196 includes a threaded aperture at 196 a. Finally, a cross tube 198 is positioned at a rear of frame member 22 and includes threaded apertures 198 a. Brackets 200 are positioned intermediate cross tubes 182 and 190 to retain chain tensioner 166 and bracket 202 is attached to frame member 180 to attach drive member 160. Upper frame members 210 extend from cross tube 182 rearwardly to cross tube 198 and include reinforcing frame members 212 a, 212 b, and 212 c.

Upper frame portion 154 (FIGS. 9-11) further includes the side panels 26 and more particular left side panel 26 a and right side panel 26 b coupled to the upper frame member 22. As shown best in FIGS. 9 and 11, side panel 26 a is formed of a panel, such as an aluminum or stainless steel panel and is configured to couple to the left side of upper frame member 22. In particular, panel 26 includes apertures to receive fasteners 222 a which couples to threaded aperture 192 a (FIG. 12), fastener 222 b to couple threaded fastener 196 a (FIG. 12) and fastener 222 c to fasten to threaded aperture 198 a (FIG. 12). As shown in FIG. 11, left side panel 26 a further includes apertures 230 a and 230 b for coupling to the intermediate suspension portion 156 as will be described herein. As shown in FIG. 11, side panel 26 a further includes apertures 230 c and 230 d for receipt therethrough of a driveshaft for drive member 160 and an aperture for receipt of drive shaft for belt drive 162.

With reference now to FIG. 10, right hand side panel 26 b includes apertures for receipt of fasteners 240 a (for coupling with aperture 190 a); fastener 240 b (for coupling with threaded aperture 196 a) and fastener 240 c (for coupling with threaded aperture 198 a). Side panel 26 b also includes apertures for receipt of fasteners 242 a and 242 b which couple with intermediate suspension portion 156 as described herein. Side panel 26 b also includes a mounting area 244 for coupling belt drive 162 (FIG. 7).

With reference again to FIG. 11, intermediate suspension 156 is comprised of a front control arm 250, a front shock absorber at 252, a rear control arm 254, and a rear shock absorber at 256. As shown, front control arm 250 has an upper axle at 260 and a lower axle at 262. Upper axle 260 includes threaded apertures 260 a and lower axle 262 includes threaded apertures 262 a. Shock absorber 252 is coupled to upper axle 260 at 266 and includes a lower axle at 268 having a threaded aperture 268 a. Rear control arm 254 includes an upper axle 270 having a threaded aperture at 270 a and a lower axle 272 and mounted between slide rails 24, as described herein.

With reference now to FIG. 14, lower axle assembly 272 includes a spacer 274 having threaded apertures at 274 a and axle 276 is slidably receivable over spacer 274 and sleeves 278 which are received in open ends 280 of axle member 276. As shown, when spacer 274 is received through sleeves 278 and axle member 276, fasteners 282 a and 282 b may be received through washers 284, through apertures 286 of slide rails 24 such that axle member is rotatable about spacer 274. It should be appreciated that the spacer 274 is slightly longer than the axle 276, allowing the axle 276 to rotate about spacer 274. Axle member 276 includes link arms 288 having apertures at 288 a for coupling to rear control arm 254. With reference again to FIG. 11 rear control arm 254 includes threaded apertures 254 a at a lower end thereof that may be coupled to apertures 288 a (FIG. 14) with fasteners (not shown). With respect still to FIG. 11, rear shock absorber 256 includes a lower axle 290 having a threaded aperture at 290 a.

In addition to apertures 286 (FIG. 14) slide rails 24 also include apertures 300, 302, and 304 (FIG. 11). Thus, and with reference to FIG. 11, intermediate suspension portion 156 may be coupled to slide rails 24 by way of fasteners through apertures 302 into threaded apertures 268, by fasteners extending through apertures 304 into threaded apertures 262 a and fasteners through apertures 300 and into threaded aperture 290 a.

With reference now to FIGS. 15-18, bumper assembly 170 will be described in greater detail. As shown in FIG. 15, bumper assembly 170 is shown mounted to slide rail 24 above a slot 310 of slide rail 24. Bumper assembly 170 generally includes a plunger at 312, a spring grommet 314 and a carrier mount at 316. With reference now to FIG. 16, the bumper assembly 170 is shown exploded away from slide rail 24. As shown, plunger 312 includes a head portion 312 a, a shank portion 312 b and a threaded aperture at 312 c (see FIG. 17). Spring grommet 314 includes a pair of resilient bellows 314 a and 314 b coupled to a base portion 314 c with an aperture 314 d extending downwardly through spring grommet 314 and profiled to receive plunger 312. Carrier mount 316 includes flanges 316 a which flank a base portion 318 which includes an aperture 320 profiled to receive shank portion 312 b of plunger 312 as described herein.

To assemble the bumper assembly, plunger 312 is installed through aperture 314 d of spring grommet 314 with base portion 314 c positioned on base 318 of carrier mount 316. If desired, a thrust washer could be positioned under the head portion 312 a and above the spring grommet 314. Fastener 322 may then be positioned through washer 324 and threadably received into threaded aperture 312 c of plunger 312. Fasteners 326 are then positioned through apertures 316 b of flanges 316 a to couple the bumper assembly to threaded apertures 328 on slide rail 24. A cross-sectional view of FIG. 17 shows the bumper assembly as applied to the side of slide rail 24. As should be appreciated from FIG. 17, flanges 316 a are offset asymmetrically with base 318 of mount 316 such that the plunger is centered with the slot 310. Thus, as shown in FIG. 18, during a jounce, rear control arm 254 collapses and is aligned with bumper assembly 170, and in particular with the head portion 312 of plunger 312, causing spring grommet 314 to compress causing the shank portion 312 b to extend into slot 310.

With reference now to FIGS. 19-30, a second embodiment of a rear suspension will be described. With reference to FIG. 19 a second rear suspension is shown at 420 having a frame 422 with a single slide rail 424 where carrier rollers 425 flank single side rail 424. Rear suspension 420 further includes side panels 426, a front control arm 428, rear control arm 430, front shock absorber 432 and rear shock absorber 434. As in the first embodiment, rear suspension 420 includes an input drive 460, belt drive 462 coupled together by way of chain case 464, a chain tensioner 466 and a braking system 468. Rear suspension 420 further includes a rear bumper assembly 470 as described herein. With reference now to FIGS. 20-25, chain tensioner 466 will be described in greater detail.

As shown first in FIGS. 20 and 21, frame 422 includes a front cross bar at 482 with elongate extension bars 488 coupled to cross bar 482 and extending generally forward. Sliding mounts 490 are coupled to elongate extension bars 488 and are slidable relative thereto. Chain tensioner 466 further includes a locking mechanism at 492 and a chain guide at 494.

As shown best in FIG. 22, elongate extension bars 488 include an inner end at 500 which is coupled to the cross bar 482, an inner surface 502 which is substantially flat, and an outer surface at 504 having triangulated edges at 506. Each of the bars 488 includes apertures at 510. As shown in FIGS. 23 and 24, sliding mounts 490 are shown, where in FIG. 23 an inner surface 514 is shown having an integrated channel at 516. The channel 516 includes upper and lower surfaces 516 a, an inner flat surface at 516 b, and triangulated surfaces 516 c, which as should be appreciated, align with and cooperate with triangulated surfaces 506 on bars 488. Apertures 520 extend through inner surface 516 b and are slotted in a longitudinal direction.

As shown in FIG. 24, sliding mounts 490 include an outside flattened surface at 522. A front end 524 of the sliding mount 490 includes a coupler at 526 which is substantially similar to coupler 184 (FIG. 12) to couple the rear suspension 420 to the motorcycle frame. However, in this embodiment, the chain is tightened by providing longitudinal flexibility in the position of the rear suspension relative to the motorcycle frame. In that regard, fasteners 528 (FIG. 22) are provided which are receivable through slotted apertures 520 and into threaded engagement with threaded apertures 510. The triangulated surfaces 506, 516 c allows vertical alignment of the sliding mounts relative to the bars 488 and positioning fasteners 528 into threaded engagement with threaded apertures 510 allows sliding mounts 490 to be moveable longitudinally to the extent of the slotted apertures 520, as described further herein.

With reference now to FIG. 22, locking mechanism 492 will be described. As shown in FIG. 22, cross bar 482 includes an aperture at 482 a and has an undercut portion at 482 b. The locking mechanism is comprised of O-rings 530, a rod 532, a locking cam 534 and fasteners 536, 538. Rod 532 has an aperture at 532 a and a flattened surface at 532 b. Locking cam has an eccentric lobe at 534 a and an aperture at 534 b having flattened inner surfaces at 534 c. Fastener 536 has flattened surfaces at 536 a.

Thus, once the rear suspension 420 is positioned on the motorcycle frame, the rear suspension can be moved rearwardly to tighten the chain whereupon the threaded fasteners 528 can be tightened to the position to retain sliding mounts 490 relative to bars 488. At this point, the O-rings 530 can be received over each end of the cross bar 482 and be received in the undercut portion 482 b. Rod 532 is then received into aperture 482 a and locking cams 534 are positioned over the ends of rod 532 aligning the flattened surfaces 532 b, 534 c. Fasteners 536 may be received in aperture 534 b and fasteners 538 may be brought into threaded engagement with threaded apertures 532 a of rod 532. Two wrenches may now be used to bring the locking mechanism into a full locking condition, for example, a box wrench or adjustable wrench may be used with fastener 536 whereby a torque may be applied to the locking cam 534 to position it against the sliding mount 490. At the same time, a second wrench such as an allen wrench may be used to tighten the fasteners 538 to bring the locking mechanism in a fully locked position.

This is shown in diagrammatic form in FIGS. 25A and 25B where in the position of FIG. 25A sliding lock 490 is moved to the full left position into the direction of arrow A and locking cam 534 is rotated in the counter-clockwise direction until it abuts the end of sliding 490. In this position, a distance between the center of the mounting member 526 and the fastener 538 is a distance D₁. With reference now to FIG. 25b , the sliding mount 490 is moved to the fully right hand position in the direction of arrow B and locking cam 534 is rotated in a clockwise position to accommodate the lateral movement of the locking mount 490. The corresponding distance in this position is D₂, where D₁ is greater than D₂.

With reference now to FIGS. 26-39, bumper assembly 470 will be described in greater detail. As opposed to the first embodiment of rear suspension 20 where the bumper assembly 170 was provided on the slide rail, and the control arm rotated into the bumper assembly, this embodiment is exactly the opposite; that is, the bumper assembly 470 is mounted to the control arm 430 and the movement of the control arm downwardly provides contact between the slide rail 424 and the bumper assembly 470.

As shown best in FIGS. 27-29, the control arm 430 includes two arm members 550 (FIG. 29) with a lower coupler 552 which mounts to a link assembly 554 (FIG. 26) and an upper coupler at 560 which couples to side panels 426 (FIG. 26). Rear control arm 430 further includes a mount or bracket at 562 having a base portion 564 with an aperture 566 extending therethrough. Bumper assembly 470 is substantially similar to bumper assembly 170 including a plunger 582, spring grommet 584, fastener 592 and washer 594. The fully assembled position of the bumper assembly 470 is shown in FIG. 27 where plunger 582 is positioned through spring grommet 584 with fastener and washer positioned against base portion 564 and fastener 592 threaded into threaded engagement with threaded aperture 590 (FIG. 28).

As shown in FIG. 30, in this embodiment, when rear control arm 430 rotates in the direction downwardly in the direction of arrow C, plunger 528 contacts an upper edge 424 a of slide rail 424. The extent of travel upwardly of plunger 528 is shown by the difference between the plunger 528 in solid lines versus plunger 528 in phantom lines.

With reference now to FIGS. 31-40, a third embodiment of a rear suspension will be described. With reference to FIG. 31 a third rear suspension is shown at 620 having a frame 622, slide rails 624, top tunnel portion 625, side panels 626, a front control arm 628, rear control arm 630, front shock absorber 632 and rear shock absorber 634. A progressive rate linkage 635 is coupled between the rear control arm and the frame as described herein. As in the first embodiment, rear suspension 620 includes an input drive 660, belt drive 662 coupled together by way of chain case 664, and a chain tensioner 666. With reference now to FIGS. 32-34, frame 622, side panels 624 and top tunnel 625 will be described in greater detail.

With reference first to FIGS. 33 and 34, frame 622 is shown as a unibody construction having an elongate frame member or spine 700 with a generally rectangular cross-section. Spine 700 has side walls 702 with a front-end at 704, a rear end at 706, a lower wall 708 and a top wall 710. Frame member 700 could be manufactured from one or multiple sheets of rigid material such as aluminum or steel where portions of the sheet are stamped and formed into the box-shaped configuration shown in FIGS. 33 and 34 and bonded together such as by welding or industrial adhesives and the like. Frame member 700 could also be manufactured from a casting, such as an aluminum casting.

Side walls 702 include an enlarged aperture 720 extending therethrough encircled by apertures 722. Apertures 720 is profiled to receive input drive 660 (FIG. 31) and attached thereto by way of fasteners through apertures 722. Frame 622 further includes four cross bars; a first cross bar 726, a second cross bar 728, a third cross bar 730, and a fourth cross bar 732. Each of the cross bars 728-732 include threaded apertures 728 a, 730 a, and 732 a respectively.

As shown best in FIG. 33, a portion of chain tensioner 666 (FIG. 31) is defined by a unitary member 740 which may be a casting or forging of metal or aluminum which includes a body portion at 742 having two coupling members 744 and 746 encircling the cross bars 726 and 728. As shown, a portion of cross bar 728 protrudes beyond the coupler 744 whereas coupler 746 encapsulates an end portion of cross bar 726. Couplers 744 and 746 may be coupled to their corresponding cross bars 728, 726 by such means as industrial adhesives, fasteners or welding. Extension bars 750 extend forwardly from couplers 746 and include elongated apertures at 752. Chain tensioner 666 further includes slide mounts 756 (FIG. 31) having apertures at 758. Chain tensioner 666 operates in substantially the same way as chain tensioner 466 with the only difference being in the location of the slotted apertures 752.

With reference again to FIG. 32, right side panel 626 include apertures 626 a, 626 b and 626 c which align with corresponding apertures 728 a, 730 a and 732 a (FIG. 34). Left side panel 626 includes a large aperture 762 to receive the chaincase 664, and apertures 730 a and 732 a. Right side panel 626 includes an aperture 764 for receiving an opposite end of belt drive 662 (FIG. 31). Each of the side panels 626 also include pairs of apertures 770 a, 770 b and 772 a, 772 b for coupling of the suspension as provided herein. Side panels 626 also include a plurality of apertures 774 for coupling of the top panel or tunnel portion 625.

As shown in FIG. 32, top panel 625 includes a stamped and formed piece of material such as aluminum or steel with a generally flat portion at 780 having folded flaps 782 at the marginal edges thereof. Inclined portions at 784 lead into top panel portions 786 having a slot 788 extending therebetween. The marginal edges 782 includes a plurality of apertures at 782 a for coupling with the plurality of apertures 774 in side panels 626 to retain the top panel 625 to the side panels 626. At the same time the slot 788 allows the top panel portions 786 to flank the frame portion 622 as best shown in FIG. 31.

With reference now to FIGS. 35-38, progressive rate linkage 635 will be described in greater detail. With reference first to FIG. 38, rear control arm 630 will be described having a lower coupler 790 having openings at 792 with frame members 794 extending upwardly and forwardly terminating in couplers at 796 having openings at 798. Midway up frame members 794 are two bracket members 800 having a portion 802 mounted to the frame member 794 and a portion 804 depending downwardly therefrom having a front aperture at 806 and a rear aperture at 808.

The mounting of rear control arm 630 to slide rails 624 is done by way of a link assembly 810 having a tubular portion 812 having threaded apertures at 812 a and an upstanding bracket at 812 b having apertures at 812 c. An axle 816 is provided having threaded apertures at 816 a. Thus, coupler 790 is coupled to brackets 812 b by positioning axle 816 through coupler 790, and by aligning apertures 816 a and 812 c together, whereupon fasteners 818 and washers 820 can couple control arm 630 to link assembly 810. That combination may be coupled to the slide rails 624 by positioning a fastener (not shown) through apertures 822 a (FIG. 35) and threadably engaging threaded apertures 812 a.

A triangular link assembly 830 is shown in FIG. 35 coupled to bracket 800. As shown in FIG. 38, triangular link assembly 830 includes a triangular link 832, an adjustable link 834 and an axle at 836. As shown best in FIG. 38, triangular link 832 has three pivotal points at 832 a, 832 b and at enlarged opening 832 c. Adjustable link 834 includes a shank portion at 834 a and a coupler at 834 b. Shank portion 834 a includes a threaded aperture at 834 c and coupler 834 b includes an opening at 834 d. Adjustable link 834 also includes a ball joint portion 834 e having a ball joint with an aperture at 834 f Adjustable link is assembled by threading nut 834 g onto threaded portion 834 e and then threading threaded portion 834 e into threaded aperture 834 c. It should be appreciated that the linear length of the adjustable link 834 may be adjusted by the location of the lock nut 834 g relative to the shank portion 834 a. Adjustable link 834 is now positioned over axle 836 with bushings 838 positioned in apertures 834 d. Couplers 840 may now be slidably received over axle member 836 and against coupler 834 b and locked in place.

Axle 836 may be coupled to slide rails 624 by inserting a fastener (not shown) through apertures 822 b (FIG. 35) and aligning them with the apertures 836 a (FIG. 38). It should be appreciated that ball joint opening 834 f is coupled to triangular link aperture 832 a by way of a fastener 832 d. It should also be appreciated that aperture 832 c of triangular link 832 is coupled to aperture 808 of bracket 800. To that end, aperture 832 c receives bearings 850 a, spacer 852 a, grommets 854 a and washers 856 a. That assembly is then positioned relative to aperture 808 of bracket 800, whereby fasteners 858 a may be received through apertures 808 and threaded into spacer 852 a.

Linkage 635 further includes a link 870 having a coupler 872 and 874. Coupler 872 may be coupled to aperture 832 b of triangular link 832 by positioning bearings 850 b in each of the couplers 872 and 874 followed by spacers 852 b and washers 856 b. A fastener 858 b may then be positioned into aperture 832 b through the spacer 852 b and coupler 872 and into a threaded aperture on the opposite side of the triangular link 832.

Linkage 635 further includes a link 880 having a lower coupler at 882 having an aperture at 882 a and two link arms 884 having apertures at 886 and 888. Link 870 is coupled to link 880 by way of a fastener 858 b extending through aperture 888 of link 880 and through bearing 850 b, spacer 852 b, washers 856 b and coupling opening 874 of link 870. Meanwhile, link 880 is coupled to bracket 800 by positioning bearings 850 c, spacer 852 c, grommet 854 c and washer 856 c in aperture 882 a, whereupon a fastener 858 c may be received through opening 882 a of link 880 and through aperture 806 of bracket 800. This couples both the triangular link 832 and the link 880 to the bracket 800, with the link 870 coupled between the triangular link 830 and link 880.

Finally, shock absorber 634 may be installed in the assembly. Shock absorber 634 includes a coupling at 634 a which couples to aperture 886 of link 880. Upper end of shock 634 includes a coupling 634 b coupled to an axle member 900 (FIG. 36) which is shown in FIG. 35 as coupled to an inside of side panels 626. Namely axle 900 includes brackets 902 having apertures at 902 a which may receive fasteners therethrough and into side panel 626.

In operation, and with reference to FIGS. 36 and 37, when the control arm 630 begins to rotate in a downward sense, triangular link 832 will rotate about bracket 800 causing link 870 to push the link 880 forward. As link 870 is coupled to a midpoint of link 880, the shock is compressed or stroked at a greater rate than it would with a direct connection. This is also shown diagrammatically in FIGS. 39 and 40 where control arm is moved from the position shown in FIG. 39 to a collapsed position shown in FIG. 40. This movement causes triangular link 832 to rotate in the clockwise sense (as viewed in FIGS. 39 and 40) which causes link 870 to push link 880 forward and due to the connection of the shock 634 to the upper end of link 880, the shock is stroked at a greater rate and at a progressive rate.

Alternatively, and with respect to FIG. 36A, adjustable link 834 could be coupled directly to the tubular portion 812 of link assembly 810.

With reference now to FIGS. 41-43, the application of the chain case 664 to the belt drive 662 will be described in greater detail. As shown best in FIG. 41, chain case 664 includes a drive portion 920 and a cover 922. Drive portion 920 includes housing 924 having an outer flange 926 that overlaps opening 762 and a reduced profile portion 930 (FIG. 43) which protrudes through opening 762.

As shown best in FIG. 42, input drive 660 includes a sprocket 934 having an output coupler 936 for coupling to input driveshaft 938 of chain case 922. A drive sprocket is shown as coupling to a sprocket 940 which is driven by a belt or chain. A driven sprocket 942 is coupled to the drive sprocket 940 which in turn drives belt drive 662 by way of a drive shaft 944 to sprockets 946. An idler roller 950 is shown having a tensioner 952 for tensioning the chain or belt. Drive shaft has a shaft coupling 954 which couples to a bearing 956 mounted on an inside of side panel 626.

Due to the compactness of the suspension frame 622, the volume of space beneath the frame 622 is open, which allows the belt drive 662 as assembled to the drive portion 920 (as shown in FIG. 42) to be installed through the opening 762 and under the frame 622, to a position where shaft coupling 954 couples to the bearing 956. Drive portion 920 may be coupled to side panel 626, by way of a fastener 960 positioned through aperture 962 and threadably engaged with threaded aperture 728 a; as well as with fasteners 964 (such as rivets) positioned through aperture 968 and engaged with aperture 762 a.

With reference now to FIG. 1, the location of the drive axis of the belt drive is shown as Ai, where a vertical distance from the top of the foot peg 38 to drive axis distance Ai is shown as Y, and a horizontal distance from the center of the foot peg 38 to drive axis Ai is shown as X. An attempt has been made in the embodiments herein to move the drive axis Ai up out of the snow of the snow as much as possible for deep snow applications. Thus for the embodiments of FIGS. 7 and 31, the dimension X is in the range of 6.222″ to 7.922″ and more specifically in the range of 7.000″-7.500″. In the embodiment shown X=7.422″. For the embodiments of FIGS. 7 and 31, the dimension Y is in the range of 3.400″-5.400″ and more specifically in the range of 3.750″-4.500″. In the embodiment shown Y=3.900″.

Thus, as the foot peg 38 locates the rider, an attempt has been made to keep the distance Y to a minimum. As the foot peg 38 tends to dictate the location of the rider, the distance X was selected to center the driver's mass with the mass of the vehicle.

Although a chain case is shown in the embodiments of FIGS. 7, 19 and 31, a belt drive could be used such as that shown in U.S. Pat. No. 8,919,477, the subject matter of which is disclosed herein by reference. This belt drive is designed to not require a tensioning device, such that the belt drive of U.S. Pat. No. 8,919,477 could replace any of the aforementioned chain cases 164, 464, and/or 664.

With reference now to FIGS. 44-48C, a second embodiment of the front suspension assembly will be described. As shown best in FIGS. 44-46, front suspension assembly 216 is shown, but in this embodiment, the suspension 216 is coupled to two skis 218 (Left ski 218L and right ski 218R). Front suspension assembly 216 generally includes a spindle body 240, and a lower linkage portion 242. The front suspension 216 would also include a mounting portion similar to that as shown at 44 in FIG. 3, for connection to the forks 12. In this embodiment, front suspension assembly 216 includes an independent suspension for each one of the skis 218, as discussed herein.

As shown best in FIGS. 47-48C, spindle body 240 is generally comprised of two plates 250 and 252 where each plate includes a plurality of apertures. Namely, plate 250 includes apertures 250 a-250 c together with enlarged apertures at 250 d-250 f. Likewise, plate 252 includes apertures 252 a-252 c and enlarged apertures at 252 d-252 f Spindle body 240 also includes a plurality of spacers to space the plates 250 and 252 apart, namely spacers 254 a, 254 b, 254 c, 254 e and 254 f. An enlarged spacer is provided at 254 d. It should be noted that each of the spacers 254 e and 254 f are somewhat spool-shaped having an enlarged head portion 256 (FIG. 48A) at each end as well as threaded openings 258 at each end (FIG. 48A). Enlarged head portion 256 defines reduced diameter portion 256 a and shoulder 256 b (FIG. 48A). Enlarged spacer 254 d is embossed at each end to define a reduced diameter section 260 defining shoulders 262 (FIG. 48A).

Thus, the spindle body 240 may be preassembled by placing the spacers 254 d, 254 e and 254 f between the plates 250 and 252. This is done by placing the reduced diameter portions 260 of spacer 254 d into respective apertures 250 d and 252 d; by placing the reduced diameter portions 256 a of spacer 254 e into respective apertures 250 e and 252 e; and by placing the reduced diameter portions 256 a of spacer 254 f into respective apertures 250 f and 252 f (FIGS. 47 and 48A). This positions the reduced diameter portions 260 through their corresponding apertures as shown in FIG. 44. This also positions the reduced diameter portions 256 a through their corresponding apertures (250 e, 250 f; 252 f, 252 f) as the shoulders 256 b abut the plates 250, 252.

Spacers 254 a and 254 c are also installed by aligning them with corresponding apertures 250 a, 252 a and 250 c, 252 c. Fasteners may then be positioned against plates 250 and 252 to retain the two plates together and coupled to the spacers. Namely, fastener 270 a (FIG. 48A) may be aligned with aperture 250 a of plate 250 and brought into threaded engagement with threaded aperture of spacer 254 a. Likewise, fastener 270 a may be aligned with aperture 252 a of plate 252 (FIG. 47) and received into the threaded aperture of spacer 254 a. Also fastener 270 c (FIG. 48A) may be aligned with aperture 250 c of plate 250 and brought into threaded engagement with threaded aperture of spacer 254 c. Likewise, fastener 270 c may be aligned with aperture 252 c of plate 252 (FIG. 47) and received into the threaded aperture of spacer 254 c.

With reference still to FIGS. 47-48C, the link assembly 242 will be described in greater detail. As shown best in FIG. 47, link assembly 242 includes two independent suspensions, namely a right suspension 264 and a left suspension 266. Right suspension 264 includes a front link or control arm 300 and a rear link or control arm 302. As shown best in FIG. 48A, control arm 300 includes an upper coupling 300 a and a lower coupling at 300 b. Likewise, control arm 302 includes an upper coupling at 302 a and a lower coupling at 302 b. Left suspension 266 includes a front link or control arm 304 and a rear link or control arm 306. Control arm 304 (FIG. 47) includes an upper coupling 304 a and a lower coupling at 304 b (FIG. 48B). Likewise, control arm 306 includes an upper coupling at 306 a and a lower coupling at 306 b (FIG. 48B).

Each of the upper couplings 300 a and 302 a receive sleeves 305 (FIG. 48A) which are profiled to be received in the couplings 300 a, 302 a. Couplings 300 a and 302 a of control arms 300 and 302 are then positioned over the reduced diameter portions 256 a of spacers 254 e and 254 f which protrude through apertures 250 e 250 f Thus, control arms 300 and 302 of right suspension 264 may be aligned with respective apertures 250 e and 250 f, (FIG. 48A) and fastened to the spindle assembly by way of fasteners and washers 270 e, 272 e and 270 f, 272 f In a like manner, control arms 304 and 306 of left suspension 266 also receive sleeves 305 (FIG. 47) and are then positioned over the reduced diameter portions 256 a of spacers 254 e and 254 f which protrude through apertures 252 e, 252 f of plate 252 (FIG. 47). Thus, control arms 304 and 306 of left suspension 266 may be aligned with respective apertures 252 e and 252 f, (FIG. 47) and fastened to the spindle assembly by way of fasteners and washers 270 e, 272 e and 270 f, 272 f.

With reference again to FIG. 48A, linkage assembly 242 further includes a knuckle 310 having a front pivot coupling 310 a having a threaded aperture at 310 b and a rear pivot coupling 310 c having a threaded aperture 310 d. Spacer 311 and sleeves 312 may be received in lower couplings 300 b, 302 b of control arms 300, 302 whereupon lower couplings 300 b, 302 b may be received in front and rear pivot coupling 310 a, 310 c and fasteners 314 may be received in alignment with threaded apertures 310 b, 310 d to couple control arms 300, 302 with the knuckle 310.

Finally, with reference to FIG. 48C, linkage 242 further includes shock absorbers 324, 325 having lower couplings at aperture 324 a, 325 a and upper couplings at 324 b, 325 b. Split sleeves 326, 327 include reduced diameter portions 326 a, 327 a. Split sleeves 326 may be positioned with reduced diameter portions 326 a in apertures 324 b of shock absorber 324. Likewise, split sleeves 327 may be positioned with reduced diameter portions 327 a in apertures 325 b of shock absorber 325. The shock absorbers 324, 325 may then be coupled to the spindle assembly by way of spacer 254 b. That is, spacer 254 b is positioned through sleeves 326, 327 with spacer 254 b aligned with apertures 250 b, 252 b. Fasteners 272 b are then inserted through apertures 250 b, 252 b and into threaded apertures of spacer 254 b. This pivotally couples the two shock absorbers 324 and 325 to the spindle 240.

The lower apertures 324 a, 325 a of shocks 324, 325 may then be coupled to control arms 302, 306 as shown in FIG. 48C. A first sleeve 330 is positioned with a reduced diameter portion 330 a within aperture 324 a of shock 324. The sleeve 330 and the shock aperture 324 a are then aligned with aperture 302 d on boss 302 e whereupon fastener 340 may be received through sleeve 330 and into aperture 302 d. Likewise, a second sleeve 332 is positioned with a reduced diameter portion 332 a within aperture 325 a. The sleeve 332 and the shock aperture 325 a are then aligned with an aperture (not seen in FIG. 48C) on boss 306 e whereupon fastener 342 may be received through sleeve 332 and into the aperture.

Thus, the entire assembled second suspension system 216 is shown in FIGS. 44-46 where knuckle 310 is shown as providing an aperture 310 e (FIG. 48B) for coupling to ski 218 as shown. That is, ski 218 includes ski rails 218 a whereby a pin 218 b may be received through the rails and into aperture 310 e for retaining ski 218 to the second suspension system 216.

Thus, in operation and with reference to FIGS. 44-46, skis 218R and 218L are shown in a fully down position as the right and left suspensions are shown in their respective extended positions. However, as the suspensions 264, 266 are independent, either ski 218R or 218L may move relative to the other. For example, as shown FIGS. 48-53, the left suspension 266 is shown in a collapsed position, whereas the right suspension 264 is shown in a fully extended position. This can be seen in FIG. 50 where the shock absorber 324 is shown in its original and fully extended position, whereas shock absorber 325 is shown fully collapsed. This can also be seen in the comparison of FIGS. 52 and 53, where in FIG. 52, the control arms 304 and 306 are shown in their collapsed position, whereas in FIG. 53, the control arms 300 and 302 are shown in their fully extended position. As in the previous embodiment, and as best shown in FIG. 52, when control arms control arms 304 and 306 are collapsed with the shock absorber 324 in a stroked position, the left ski 218L is lifted up relative to right ski 218R. It also moves rearwardly, as in the previous embodiment, having the advantages as previously enumerated. In addition ski 218L is rotated slightly in the clockwise direction, as viewed in FIG. 52.

In the second embodiment, the independent movement of the skis relative to each other has its advantages. First, as there are two skis 218, the skis may provide a wider base than a single ski providing better stability and steering capability. Second, as the skis 218 may move relative to each other, one of the skis (for example left ski 218L in FIGS. 54-55) may be lifted to pass over an object 400, which provides greater stability to the snow bike as the right ski 218R maintains contact with the ground. This provides the ability for one of the skis to be lifted up and over the object without losing control of the snow bike or without a large jolt to the front end of the snow bike. Third, and with reference to FIG. 56, when the snow bike is traversing a side slope, the skis can track with the slope to provide two levels of ski contact with the slope for better stability. Finally, due to the four bar linkage design the amount of ski trail may be adjusted versus the suspension ravel, where ski trail equals the length of the skag or the runner is behind the ski pivot bolt. Thus the ski trail can be adjusted throughout the stroke of the suspension and that can all be dependent of the four bar linkage.

In another embodiment, the two shocks can be adjusted to act differently from each other. For example, a crossover tube 420 (FIG. 49) between the shocks causes the skis to actuate oppositely. That is, when one shock is stroked, it pushes the other down, as the dampening medium is pushed from the stroked shock to the extending shock. This also helps in steering. The crossover tube 420 connects the air flow shocks such that when you lean left, the inside ski lifts up easier and then applies pressure to the outside ski because it's equalizing pressure between the two shocks so it's less rising rate on the inside ski and more of a rising rate on the outside ski which helps it maneuver the corner better than if the two shocks weren't connected between each other.

In another embodiment, a connecting rod or sway bar could be coupled between the skis to couple the two shock absorbers together.

While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains. 

What is claimed is:
 1. A snow vehicle comprising: a vehicle frame; a propulsion unit coupled to the frame; at least one front ski; a steering mechanism coupled to the frame; a first front suspension coupled to the frame; a rear suspension coupled to the frame, the rear suspension comprising: at least one slide rail; at least one control arm coupled between the slide rail and the frame; at least one linear force element coupled between the slide rail and the frame; and at least one carrier roller coupled to the at least one slide rail and the frame; a bumper assembly having a spring force and coupled to the at least one slide rail; and a drive system comprising a drive track slidably guided by the at least one slide rail and drivably coupled to the propulsion unit.
 2. The snow vehicle of claim 1, wherein the rear suspension comprises a suspension frame.
 3. The snow vehicle of claim 2, wherein the vehicle frame is a motorcycle frame and the suspension frame is coupled to the motorcycle frame.
 4. The snow vehicle of claim 1, wherein the bumper assembly is coupled to the rear suspension and positioned to prevent contact of the at least one control arm and a remaining portion of the rear suspension.
 5. The rear suspension of claim 4, wherein the bumper assembly is mounted intermediate the at least one control arm and the at least one slide rail, and the bumper assembly resiliently contracts during jounce.
 6. The rear suspension of claim 5, wherein the bumper assembly comprises a spring grommet and a carrier mount.
 7. The rear suspension of claim 6, wherein the bumper assembly further comprises a plunger extending through the spring grommet.
 8. The rear suspension of claim 7, wherein the plunger comprises a head portion and a shank portion.
 9. The rear suspension of claim 8, wherein the spring grommet includes an aperture extending downwardly therethrough and profiled to receive the plunger.
 10. The rear suspension of claim 6, wherein the spring grommet includes a pair of resilient bellows coupled to a base portion.
 11. The rear suspension of claim 10, wherein the carrier mount includes flanges which flank a base portion of the carrier mount.
 12. The rear suspension of claim 5, wherein the bumper assembly is mounted on the at least one slide rail and the at least one control arm contacts the bumper assembly during jounce.
 13. The rear suspension of claim 12, wherein the at least one slide rail comprises two slide rails and the at least one control arm comprises two control arms, and wherein the bumper assembly is mounted on the slide rails and the control arms contact the bumper assembly during jounce.
 14. The rear suspension of claim 12, wherein the at least one slide rail is slotted at a top edge thereof, and the bumper assembly is mounted over the slot.
 15. The rear suspension of claim 14, wherein the bumper assembly comprises a plunger which aligns with the slotted slide rail, and the plunger moves into the slot during jounce.
 16. The rear suspension of claim 5, wherein the bumper assembly is mounted on the at least one control arm and the bumper assembly contacts the at least one slide rail during jounce.
 17. The rear suspension of claim 16, wherein the at least one control arm comprises a bracket which mounts the bumper assembly thereto.
 18. A rear suspension for a snow vehicle, comprising: at least one slide rail; a frame; at least one control arm coupled between the slide rail and the frame; at least one linear force element coupled between the slide rail and the frame; at least one carrier roller coupled to one of the slide rail and the frame; a drive system comprising a drive track slidably guided by the at least one slide rail and drivably coupled to the propulsion unit; and a bumper assembly coupled to the rear suspension and positioned to prevent contact of the at least one control arm and a remaining portion of the rear suspension, and the bumper assembly including at least a portion configured to move within a portion of the at least one slide rail.
 19. The rear suspension of claim 18, wherein the bumper assembly is mounted intermediate the at least one control arm and the at least one slide rail, and the bumper assembly resiliently contracts during jounce.
 20. The rear suspension of claim 19, wherein the bumper assembly is mounted on the at least one slide rail and the at least one control arm contacts the bumper assembly during jounce.
 21. The rear suspension of claim 20, wherein the at least one slide rail comprises two slide rails and the at least one control arm comprises two control arms, and wherein the bumper assembly is mounted on the at least one slide rail and the control arms contact the bumper assembly during jounce.
 22. The rear suspension of claim 20, wherein the at least one slide rail is slotted at a top edge thereof, and the bumper assembly is mounted over the slot.
 23. The rear suspension of claim 22, wherein the bumper assembly comprises a plunger which aligns with the slotted slide rail, and the plunger moves into the slot during j ounce.
 24. The rear suspension of claim 19, wherein the bumper assembly is mounted on the at least one control arm and the bumper assembly contacts the at least one slide rail during jounce. 